Changing correlations among ADMA, NO and hs-CRP in normoalbuminuric and microalbuminuric patients with type 2 diabetes

Quantitative, Targeted Analysis of Gut Microbiota Derived Metabolites Provides Novel Biomarkers of Early Diabetic Kidney Disease in Type 2 Diabetes Mellitus Patients

Diabetic kidney disease (DKD) is one of the most debilitating complications of type 2 diabetes mellitus (T2DM), as it progresses silently to end-stage renal disease (ESRD). The discovery of novel biomarkers of early DKD becomes acute, as its incidence is reaching catastrophic proportions. Our study aimed to quantify previously identified metabolites from serum and urine through untargeted ultra-high-performance liquid chromatography coupled with electrospray ionization-quadrupole-time of flight-mass spectrometry (UHPLC-QTOF-ESI+-MS) techniques, such as the following: arginine, dimethylarginine, hippuric acid, indoxyl sulfate, p-cresyl sulfate, L-acetylcarnitine, butenoylcarnitine and sorbitol. The study concept was based on the targeted analysis of selected metabolites, using the serum and urine of 20 healthy subjects and 90 T2DM patients with DKD in different stages (normoalbuminuria-uACR < 30 mg/g; microalbuminuria-uACR 30-300 mg/g; macroalbuminuria-uACR > 300 mg/g). The quantitative evaluation of metabolites was performed with pure standards, followed by the validation methods such as the limit of detection (LOD) and the limit of quantification (LOQ). The following metabolites from this study resulted as possible biomarkers of early DKD: in serum-arginine, dimethylarginine, hippuric acid, indoxyl sulfate, butenoylcarnitine and sorbitol and in urine-p-cresyl sulfate.

Nitric oxide and TNF-α are correlates of diabetic retinopathy independent of hs-CRP and HbA1c

PURPOSE

Regarding the role of inflammation in progression of diabetes this study was conducted to investigate the association between inflammatory biomarkers such as nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and high-sensitivity C-reactive protein (hs-CRP) with the chance of existence of diabetic retinopathy and its progression in patients with diabetes.

METHODS

A total of 83 patients with T2DM (Type 2 diabetes mellitus) were divided into three groups of patients with proliferative diabetic retinopathy (PDR), patients with non-proliferative diabetic retinopathy (NPDR) and patients without diabetic retinopathy (NDR) based on ophthalmologic funduscopic examination. Twenty six healthy controls were also enrolled. Blood samples were taken after 12 h of overnight fasting, NO, TNF-α, and hs-CRP were measured. Association of the level of these biomarkers with retinopathy was analyzed.

RESULTS

The levels of TNF-α, NO and hs-CRP were higher among patients with diabetic retinopathy. Multinomial Logistic Regression model showed that TNF-α and NO could predict the presence of retinopathy among patients with diabetes when adjusted for hs-CRP, HbA1c, FBS, gender, total cholesterol, triglyceride, HDL, LDL, BMI, and age (respectively OR = 1.76, CI 95% = 1.01-3.02, p = 0.046 and OR = 1.12, CI 95% = 1.05-1.18, p < 0.001); however they could not predict the severity of retinopathy. In ROC analysis AUC for TNFα was 0.849 (p < 0.001) and for NO was 0.907 (p < 0.001). Serum TNF-α level of 7.10 pmol/L could be suggestive of the presence of retinopathy (sensitivity = 92.2% and specificity = 66.0%), also serum NO level of 45.96 μmol/L could be suggestive of the presence of retinopathy (sensitivity = 96.1% and specificity = 86%).

CONCLUSIONS

Our results suggest elevated levels of NO and TNF-α can be suggestive of diabetic retinopathy.